Tuesday, June 18, 2019

Eccentricity of Wall Footing

I replied to a thread at AUGI regarding the Eccentricity parameter of a Wall Footing. They observed that Revit seemed to ignore their input and didn't understand what it was meant to do. In this case the width of the footing was less than the value they entered.

The parameter is intended to shift the footing over, from interior to the exterior face of the wall. The footing starts out centered on the wall above.

The maximum eccentricity is equal to (Footing Width/2)-(Wall Thickness/2).

The interior wall surface can be aligned (flush) with the interior face of the footing but not further, creating any overhang of the wall, which seems logical to me. A picture might help?


rspierenburg said...

This is fine for strict structural drawings. But in my case we have a foundation wall that comprises of a 10" concrete wall and 4" rigid insulation on the outside. We cannot center the footing on the concrete wall as the wall is too thick.

Steve said...

A negative eccentricity of half the insulation (2") thickness will center the 10" of concrete wall over a footing's center line.